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