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