One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,8)(4,6)(5,7)(9,10)(11,14)(12,15)(13,16)(17,21)(18,22)(19,23)(20,24)(25,26,30,35)(27,36,28,32)(29,34,31,39)(33,38,40,37)(1,3,5,4)(2,6,7,8)(9,11)(10,14)(12,19)(13,18)(15,23)(16,22)(17,20)(21,24)(25,27,30,28)(26,32,35,36)(29,38,31,37)(33,39,40,34)(9,12,13,20)(10,15,16,24)(11,17,18,19)(14,21,22,23)(25,27,30,28)(26,33,35,40)(29,37,31,38)(32,39,36,34)(1,4,5,3)(2,6,7,8)(11,18)(14,22)(17,19)(21,23)(25,28,30,27)(26,32,35,36)(29,37,31,38)(33,39,40,34)(10,16)(14,22)(15,24)(21,23)(25,29,30,31)(26,34,35,39)(27,37,28,38)(32,40,36,33)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.