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