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