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