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