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