You could try one of Messiaen's Huit Preludes Pour Piano. Number 4 is moderately difficult but beautiful, though I am not sure if it is sufficiently difficult for your senior recital.
You could also try one of the easier etudes of Ligeti (though none are
easy)such as No 4 Fanfares.
Also really worth looking into is Stravinsky. His Piano Rag Music is really worth playing, not too difficult and a really entertaining piece.
If the piece has to be by an actual living composer I would suggest Carter's Catenaires. It is a really exciting piece to listen to....
Another piece by a little known living composer, Marian Ingoldsby, is Red Shoes. It was commisioned for the AXA Dublin International Piano Competition a few years ago. It is really a beautiful piece and can be bought only from the Contemporary Music Centre in Ireland. There used to be an audio clip on
www.cmc.ie but I can't find it anymore.
Hope that this is of some help!!

Quirky