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