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