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)(13,14,19,24,20,25,18,23)(15,26,27,16,22,28,17,21)(5,6)(7,11)(8,10)(9,12)(13,15,20,22)(14,21,25,16)(17,18,27,19)(23,26,24,28)(2,4)(5,7)(6,9)(8,12)(10,11)(13,16,20,21)(14,22,25,15)(17,23,27,24)(18,26,19,28)(7,12)(9,11)(13,17,19,15,20,27,18,22)(14,21,24,26,25,16,23,28)(6,10)(9,11)(13,18,20,19)(14,23,25,24)(15,27,22,17)(16,28,21,26)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.