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