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