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