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