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)(11,15)(12,14)(13,16)(19,25)(23,31)(26,32)(27,29) involution — undirected(2,6)(7,8)(9,11)(10,13)(12,16)(14,15)(17,18,21,22)(19,26,25,32)(20,28,30,24)(23,29,31,27)(1,3,5,4)(2,7,6,8)(10,14)(11,16)(18,22)(23,31)(24,28)(26,32)(1,3,5,4)(2,7,6,8)(10,14)(13,15)(17,19,21,25)(18,23,22,31)(20,29,30,27)(24,32,28,26)(1,4,5,3)(2,7,6,8)(10,14)(13,15)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.