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