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