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