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