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