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