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