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