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