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