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