Going to the Grand canyon from Los Angeles by AMTRAK?

My family and I are going to the Grand Canyon by train from LA. The only train there is arrives at Flagstaff at 4:30am. From here we take a bus to Williams, where there is a direct connection into the canyon. However, there is a 3.5 hour layover at Flagstaff. Is there a 24hr restaurant near the station where we can wait for the bus? We are traveling with our 14 yr old son.