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