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