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