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