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