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