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