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