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