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