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