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