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