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