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