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