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