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