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