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