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