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