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