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