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