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