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