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