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