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