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