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