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