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