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