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