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