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