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