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