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