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