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