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