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