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