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