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