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