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