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