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