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