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