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