The numbers indicate the order in which you click on the switches 1 being the first switch followed by 2 then 3 etc. .
The images contain the starting configuration of the switch puzzles.
On the top right of each puzzle there are green and red dots. These indicate if a switch is open or closed red meaning the switch is open and green for closed. Thank you to Chrono for providing this idea.
It is possible for a switch puzzle to be rotated so if you see a configuration not listed it may be rotated.

Cheat Sheet

Thank you to -aRTY- on reddit for making the cheat sheet and allowing us to post it here.

5 Switch Puzzle

4 Switch with Gears Puzzle

Switch with Doors Puzzle