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