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