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