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