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