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