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