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