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