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