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