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