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