One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(9,10)(11,13)(12,14)(15,16)(18,23)(19,26)(20,21)(25,29)(27,28)(30,31) involution — undirected(2,4)(5,6)(7,8)(9,11,12,15)(10,13,14,16)(17,18,22,25)(19,24,28,32)(20,23,21,29)(26,30,27,31)(6,8)(17,19,22,28)(18,24,25,32)(20,26,21,27)(23,30,29,31)(10,14)(13,16)(17,20,22,21)(18,23,25,29)(19,27,28,26)(24,31,32,30)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.