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