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