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)(15,23,16,20)(17,19,27,24)(21,25,28,26)(2,4)(6,9)(10,12)(13,15)(14,20)(16,18)(17,21)(19,26)(22,23)(24,25)(27,28) involution — undirected(5,7,8,11)(6,10,9,12)(13,16,19,26,18,15,24,25)(14,21,17,20,22,28,27,23)(1,2,3,4)(13,17,19,22,18,27,24,14)(15,23,25,21,16,20,26,28)(6,9)(10,12)(14,22)(17,27)(20,23)(21,28) 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.