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