Here is the exact one I installed inline for my generator:
I chose to wire mine up with in inline fuse and a regular switch on the A/C panel next to all the other goodies like pilot light for water heater, slide extension switch, water pump switch, generator start switch, etc.
I didn't see the need to have it switch on from a 12v relay. I want this fuel pump to run regardless of what the v10 engine is doing. Since I installed the switch next to the generator start up switch inside, it makes it really easy to remember to use the switch to fire up the fuel pump.
If i put that fuel pump switch somewhere else, i might forget to switch it off when i'm done with the generator.
I had to drill a hole thru the floor and fish the 12v wires up thru the bathroom wall to get it behind the panel. There are many other wires back there, so it isn't too hard to figure out where to drill your new hole. Be sure to silicone that hole up afterwards.
Simple light bulb wiring diagram below. Just replace light bulb with fuel pump.