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