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