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