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