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