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