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