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