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