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)(11,16)(12,14)(13,18)(15,17)(19,24)(20,21)(22,23)(26,31)(27,34)(29,37)(36,39)(1,2)(3,5)(4,7)(6,8)(9,11)(10,16)(12,20)(13,17)(14,21)(15,18)(19,23)(22,24)(25,26,30,31)(27,28,34,32)(29,33,37,38)(35,36,40,39)(1,2)(3,6)(4,7)(5,8)(10,17)(11,18)(12,19)(21,22)(25,27,30,34)(26,32,31,28)(29,35,37,40)(33,39,38,36)(1,3)(2,5)(4,8)(6,7)(9,12,15,19)(10,14,17,24)(11,20,18,23)(13,22,16,21)(25,27)(26,28)(29,35)(30,34)(31,32)(33,36)(37,40)(38,39)(1,3)(2,6)(4,8)(5,7)(9,13,15,16)(10,18,17,11)(12,22,19,21)(14,23,24,20)(25,28)(26,27)(29,36)(30,32)(31,34)(33,35)(37,39)(38,40)(1,2)(3,5)(4,7)(6,8)(9,14)(10,19)(11,21)(12,17)(13,20)(15,24)(16,23)(18,22)(25,29,30,37)(26,33,31,38)(27,35,34,40)(28,36,32,39)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.