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