Research is hard.There's typing and looking at Google and all that stuff. This AP story has the following headline on ABC: "Ohio Diner Sold, Coffee-Cup Sign Used for 'Alice' Really?

So it's not the same sign, but it inspired it. Well. This was the sign in the show.

Where did Alice take place? Phoenix. Now take a look at this flickr page. Why, it's a Mel's Diner sign in Phoenix with a coffee cup that "appears to be pouring out a stream of coffee that takes the shape of an arrow." Then there's this one in Fort Lauderdale, Florida: same thing.

Lester's was a chain, it seems, and probably had more than three outlets - Ohio, Florida, and Phoenix seem too distantly spaced for a three-store chain. So the Ohio sign maybe was used for Alice. Or not. The end.