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