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)(13,14,18,23,19,24,25,22)(15,16,17,20,26,21,28,27)(1,3,4,2)(5,7,8,12)(6,9,10,11)(13,15,25,28,19,26,18,17)(14,20,23,21,24,27,22,16)(7,12)(9,11)(13,16)(14,15)(17,22)(18,27)(19,21)(20,25)(23,28)(24,26) involution — undirected(6,10)(9,11)(13,17,25,15,19,28,18,26)(14,21,23,27,24,16,22,20)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.