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)(25,26,31,35)(27,30,34,40)(28,38,37,32)(29,39,36,33)(1,2)(3,8)(4,6)(5,7)(9,11)(10,17)(12,14)(13,21)(15,20)(16,22)(18,24)(19,23)(25,27,31,34)(26,30,35,40)(28,29,37,36)(32,33,38,39)(1,3,5,6)(2,4,7,8)(9,12,16,13)(10,18,15,23)(11,14,22,21)(17,24,20,19)(25,28,31,37)(26,32,35,38)(27,36,34,29)(30,39,40,33)(1,2)(3,4)(5,7)(6,8)(9,13,16,12)(10,18,15,23)(11,21,22,14)(17,24,20,19)(25,27)(26,30)(28,36)(29,37)(31,34)(32,39)(33,38)(35,40)(1,2)(3,4)(5,7)(6,8)(9,14,16,21)(10,19,15,24)(11,12,22,13)(17,23,20,18)(25,29,31,36)(26,33,35,39)(27,37,34,28)(30,38,40,32)(1,4)(2,6)(3,7)(5,8)(9,15,16,10)(11,20,22,17)(12,23,13,18)(14,19,21,24)(25,30)(26,34)(27,35)(28,39)(29,32)(31,40)(33,37)(36,38)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.