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