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