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