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)(13,14)(15,20)(16,21)(17,19)(18,22)(23,27)(24,26)(25,28)(5,7,8,12)(6,9,10,11)(15,23)(20,27)(24,25)(26,28)(7,12)(9,11)(14,19)(16,17)(20,26)(21,22)(24,25)(27,28) involution — undirected(6,10)(9,11)(13,15)(14,20)(16,25)(17,24)(18,23)(19,26)(21,28)(22,27) involution — undirected(1,3,4,2)(13,16,18,17)(14,21,22,19)(15,24,23,25)(20,26,27,28)A 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.