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