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