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