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