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