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