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