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