A space that wide with a ceiling that low is always going to look a bit shit, unfortunately. The impressive subway stations linked are a combo of quite high spaces, and narrower spaces with lower ceilings, which can look good. But "broad wide space, low ceiling", there's really not a lot you can do.

A common approach for this sort of big low-ish train station is a partially or completely glass roof, ideally not flat, and that can look okay, but obviously not an option in this case.