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