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