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)(11,17)(12,16)(13,14)(15,19)(18,23)(20,21)(22,24)(25,26)(27,32)(28,30)(29,33)(31,35)(34,39)(36,40)(37,38) involution — undirected(2,7)(3,4)(10,14)(15,17)(16,21)(22,23)(25,27,31,39)(26,32,35,34)(28,37,29,36)(30,38,33,40)(2,7)(5,8)(12,20)(16,21)(18,24)(22,23)(25,28,31,29)(26,33,35,30)(27,36,39,37)(32,38,34,40)(1,3,6,4)(2,8,7,5)(9,11,13,19)(10,15,14,17)(12,18,20,24)(16,22,21,23)(25,29,31,28)(26,33,35,30)(27,37,39,36)(32,38,34,40)(1,4,6,3)(2,5,7,8)(9,10)(11,15)(12,16)(13,14)(17,19)(18,22)(20,21)(23,24)(25,27)(26,34)(28,36)(29,37)(30,38)(31,39)(32,35)(33,40)(1,5)(2,3)(4,7)(6,8)(9,12)(10,16)(11,18)(13,20)(14,21)(15,22)(17,23)(19,24)(25,30,31,33)(26,28,35,29)(27,38,39,40)(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.