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