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