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