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