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