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