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