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