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