B757 Captain reported the loss of the left generator in flight. The flight crew determined the left AC Bus was now also unpowered. The flight crew elected to divert and make a precautionary landing.

Narrative

During Cruise at 35;000 feet; 50 NM west of ZZZ the autopilot kicked off and numerous EICAS messages displayed. The FO (First Officer) who was PF (Pilot Flying) immediately took the airplane and began hand flying it. After looking at the EICAS messages and system lights we determined the left AC bus was off as well as the left gen. We ran the AC BUS OFF - L QRH (Quick Reference Handbook). While running the QRH I was interrupted twice by the FAs. I resumed the QRH at the wrong location and was again interrupted reading the inoperative items list. The main item that I missed was the flap indicator was inop. During approach when the FO called for flaps the indicator did not move; which was unexpected and troubling. We discontinued the approach and received vectors from ATC while we reviewed the QRH. I quickly found the mistake. In addition; I had the FO double check all the steps in the QRH while I flew and we were confident we completed all items. We used the flap speed indicators on the speed tape to confirm the flaps were moving. We returned for an uneventful landing. It was very quick from bus failure to landing. We did not have ACARS so I was unable to send a message to dispatch. We were close enough to ZZZ1 that I called ZZZ1 OPS and asked them to pass our situation to Dispatch and that we were inbound. My FMC and some other items were out on the left side so I had the FO continue to fly the plane. She did a fantastic job and I could not have asked for a better pilot in our situation.