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