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