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