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