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