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