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