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