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