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