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