Luigi, first, you should test your transformer. So you know it's wired right and the correct voltage before you connect it to the PCB. Be sure you are ready for this. Take precautions, be very careful around AC mains power. Don't leave unshielded wires exposed or loose, etc.
Here's how I understand the wiring should go with your transformer, (but we ought to verify this before connecting to the PCB).
Connect Purple and Blue together to 117 AC Neutral source (not Ground).
Connect Brown and Gray to the 117 AC Hot source.
Connect Red and Orange together, and later they will go to the middle hole near the top left on the PCB, where it says "external transformer."
You should see about 30 volts between the Black and Yellow wires.
The Black wire will go to the top hole in the PCB, and the Yellow on the bottom of the three holes.
Hopefully Greg or someone will confirm.
cheers.