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