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