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