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