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