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