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