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