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