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