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