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