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