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