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