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