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