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