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