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