One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,8)(9,10,12,14)(11,15,16,13)(17,18,21,26)(19,27,29,23)(20,25,22,24)(28,32,30,31)(1,2)(3,4)(9,11,12,16)(10,13,14,15)(17,19,21,29)(18,23,26,27)(20,30,22,28)(24,31,25,32)(2,4)(9,10)(11,13)(12,14)(15,16)(18,24)(20,22)(23,31)(25,26)(27,32)(28,30) involution — undirected(6,8)(10,14)(13,15)(17,20,21,22)(18,25,26,24)(19,28,29,30)(23,31,27,32)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.