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