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