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