First off, just try windexing the tile. The result wont be permanent, but you might be satisfied for the time being.
If not satisfied with step 1, apply a liberal amount of fabric softener to a rag and rub it into the tile. The results of this should be more lasting.
Finally, if unsatisfied with Steps 1 and 2, use a high grit sand paper to wetsand the tile until it has a nice sheen to it.