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