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