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