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