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