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