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