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