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