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