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