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