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