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