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