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