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