How to wire an American Flyer Mocel 761 Semaphore to a Lionel layout

[San Jose]

I have Model 761 American Flyer Semaphore.  It has 5 wires: black, red, green beige and yellow. 

I would like to activate it with a weight-sensitive Lionel contactor (145C or 153C).  I do not want it to control an insulated block. I just want it to operate when a train goes over the track with the contactor.  

Please give me some advice on how to wire it into a Lionel 3-rail layout. .

Thanks, San Jose