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