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