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)(13,14,19,22,18,21,17,23)(15,24,16,20,25,27,26,28)(5,6)(7,11)(8,10)(9,12)(13,15,18,25)(14,20,21,28)(16,19,26,17)(22,24,23,27)(2,4)(5,7)(6,9)(8,12)(10,11)(14,21)(15,25)(16,26)(22,23) involution — undirected(7,12)(9,11)(13,16,17,15,18,26,19,25)(14,20,23,24,21,28,22,27)(6,10)(9,11)(13,17,18,19)(14,22,21,23)(15,26,25,16)(20,27,28,24)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.