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