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)(11,12)(13,15)(14,16)(17,19)(18,20)(21,22)(23,24)(25,26)(27,30)(28,36)(29,33)(31,35)(32,38)(34,40)(37,39)(3,7)(5,8)(9,10,14,16)(11,12,17,19)(13,15,21,22)(18,20,23,24)(25,27)(26,30)(28,34)(29,35)(31,33)(32,39)(36,40)(37,38)(1,2)(3,5)(4,6)(7,8)(11,17)(12,19)(13,21)(15,22)(25,27,29,35)(26,31,33,30)(28,37,38,34)(32,39,36,40)(9,11,14,17)(10,12,16,19)(13,18,21,23)(15,20,22,24)(25,27)(26,31)(28,34)(29,35)(30,33)(32,40)(36,39)(37,38)(1,3)(2,5)(4,7)(6,8)(9,12)(10,11)(13,20)(14,19)(15,18)(16,17)(21,24)(22,23)(25,26)(27,30)(28,32)(29,33)(31,35)(34,39)(36,38)(37,40) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,13,14,21)(10,15,16,22)(11,18,17,23)(12,20,19,24)(25,28,29,38)(26,32,33,36)(27,34,35,37)(30,39,31,40)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.