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