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