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