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