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