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