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