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