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