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