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