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