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