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