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