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