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