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