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