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