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)(25,26,31,35)(27,36,38,32)(28,33,39,29)(30,37,40,34)(2,6)(3,7)(11,17)(15,21)(18,23)(22,24)(25,27,31,38)(26,32,35,36)(28,37,39,34)(29,40,33,30)(1,3)(2,4)(5,7)(6,8)(10,14)(15,21)(16,19)(22,24)(25,28,31,39)(26,29,35,33)(27,37,38,34)(30,32,40,36)(1,4)(2,3)(5,8)(6,7)(9,10)(11,15)(12,16)(13,14)(17,21)(18,22)(19,20)(23,24)(25,28)(26,33)(27,37)(29,35)(30,32)(31,39)(34,38)(36,40) involution — undirected(9,11,13,17)(10,15,14,21)(12,18,20,23)(16,22,19,24)(25,29,31,33)(26,28,35,39)(27,30,38,40)(32,34,36,37)(9,12,13,20)(10,16,14,19)(11,18,17,23)(15,22,21,24)(25,30)(26,34)(27,29)(28,32)(31,40)(33,38)(35,37)(36,39)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.