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