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