One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(13,14,18,21)(15,22,25,27)(16,20,17,26)(19,24,28,23)(5,6)(7,11)(8,10)(9,12)(13,15,17,23,18,25,16,24)(14,19,20,22,21,28,26,27)(2,4)(5,7)(6,9)(8,12)(10,11)(13,14)(15,19)(16,26)(17,20)(18,21)(22,23)(24,27)(25,28) involution — undirected(7,12)(9,11)(13,16,18,17)(14,20,21,26)(15,23,25,24)(19,27,28,22)(6,10)(9,11)(13,16,18,17)(14,20,21,26)(15,24,25,23)(19,22,28,27)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.