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