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