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