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