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