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