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