First Officer reported Captain accidentally shut off both generators while performing the after takeoff flow.

Narrative

I was flying the climb out and flap retraction was completed and the After Take-off Checklist was being commenced by the Captain (Non-Flying Pilot). I suddenly lost my PFD (Primary Floght Display); and several electrical items; and heard a loud noise on the right side. I realized the ADG (Air Driven Generator) had been deployed and transferred the controls to the Captain and requested to return and land at ZZZ. I pulled out the Aircraft X Quick Reference Non-Normal Handbook and read through ADG inadvertent Deployment Check and completed. All the normal checklists were completed and the RNAV XL loaded with landing information. We also realized we would be landing about 600 pounds overweight which would require a quick check after landing. The traffic into ZZZ was quite busy and they were able to vector us around the pattern to land quickly which seemed a better choice than flying around trying to burn fuel and get back into an arrival cue. The landing was smooth never exceeding 400 FPM descent with no other events occurring. The passengers remained on the plane until another arrived shortly from ZZZ1. Chief Pilot was contacted and an overweight report filed.Suggestions: I have witnessed several times Captains (usually just off IOE) reaching for both engine generator switches; which are located on both sides of the APU switch and am usually able to point out the wrong selection. The training department may want to reevaluate generator switch test procedures or put special emphasis on generator testing technique.