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