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