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