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