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