None of the wiring diagrams on the link Boo posted are applicable to your engine.
Briggs put out a nice little book called " engine alternator repower guide "
Google it then download the file.
There are a few diagrams showing the 2 yellow wire alternator which you have.
The only thing you are interested in is the pin out for the ignition switch.
Pull the blower housing off and locate the thine (kill ) wire to the coils.
This wire is either open circuit ( run) or closed to ground ( off ).
If it gets battery voltage for the tinest amount of time it will fry the trigger circuit inside the the coils and they will be very expensive toast.
As you have no blades you do not need a PTO switch, but a Neutral & Brake switch would be a good idea on a vehicle.
They are interupt switches which go on the starting circuit
If you are really safety conscious type then you can put one on the brake pedal as well so you have to be stationary, out of gear , with the parking brake on & have your foot on the brake to crank the engine.
Lights are of course a simple toggle switch.
Dont forget the fuse, in fact one on the lights and another on the ignition circuit would be good.
Most Vanguards have a low oil switch as well.
Do yourself a favour and get some car blade plug blocks so you can not accidently plug the wrong wires together.
The ignition switch should have tiny letters cast into the back identifing the terminals.