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