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