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