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