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