Another option is to skip the diagrams complete and just use a multimeter to test all the connections.
For example, when attempting to discover the wire purposes on the right hand control, your steps might look something like this:
1.) Set the multimeter to read resistance (200Ω setting is good).
2.) Decide on a function to discover (we'll start with the kill switch)
3.) Turn the kill switch to the 'run' position. In a bike with points or TCI ignition, this will mean we're looking for continuity. In a bike with a magneto or CDI ignition, we're looking for lack of continuity.
4.) Pick one of the wires (doesn't matter which) and connect it (alligator clips are nice, but you can hold it with your hands, too) to one of the probes on the multimeter (doesn't matter which).
5.) Using the opposite probe on the meter, start touching all of the other wires, one by one. Assuming we're work on a bike with points or TCI (95% of street bikes will fall into this category), we're looking for a reading on the meter close to zero. You will be able to see the meter switch from OL to something like 0.4.
6.) When you've found a match, switch the kill switch to off and see if the meter shows Open Line again.
7.) If so, you've the two wires associated with the kill switch. If the meter is still showing a reading (instead of Open Line) after turning the switch off, keep looking.
8.) Now that you've found the two wires, you might need to determine which is positive and which is negative. This is more likely to be an issue with modern controls because it's common for manufacturers to use a single input for power and route it, internally, into several outputs. The power wire might be used for one, many, or all of the following: Brake switch, kill switch, starter button.
9.) Determine which of the two wires you think is a power wire. Colors might help with this. Most manufacturers have a "flavor" of wire they use for power. Honda uses black as a primary color for power wires, so solid black, black/white, black/red, etc are all common colors to find on powered circuits on a Honda. Yamaha uses brown, blue, and/or red/white depending on the year. Suzuki generally uses orange, and Kawasaki can bite my ass.
10.) Using your suspected power wire from the previous step, repeat your tests checking against other wires in the bundle. For instance, let's assume you suspect that the orange/white wire is the power wire on GSXR controls (you'd be correct, but let's prove it). With one probe of the multimeter on the orange/white wire, check the next wire in the bundle and start pressing buttons or pulling levers and see if you can get your meter to show continuity. Depending on the year of your controls, you may find that the yellow/green wire will also show continuity when pressing the starter button. This is because the power coming in from the orange/white wire is used for both the kill switch and the starter button.
Expect to spend an hour or more doing these tests, but when you're done you should have a clear understanding of what is what on your controls and no diagram will be needed (at least not for the controls).