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