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