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