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