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