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