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