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)(11,12)(13,21)(14,15)(16,23)(17,20)(18,22)(19,24)(26,28)(27,33)(32,36)(35,39)(3,7)(5,8)(9,11,14,17)(10,12,15,20)(13,18,23,24)(16,19,21,22)(25,26,30,28)(27,34,33,31)(29,32,37,36)(35,40,39,38)(1,2)(3,5)(4,6)(7,8)(10,15)(11,17)(16,21)(18,24)(25,26,30,28)(27,31,33,34)(29,36,37,32)(35,40,39,38)(1,3)(2,5)(4,7)(6,8)(9,12)(10,11)(13,22)(14,20)(15,17)(16,24)(18,21)(19,23)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,40)(37,39) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,13)(10,16)(11,18)(12,19)(14,23)(15,21)(17,24)(20,22)(25,28,30,26)(27,31,33,34)(29,36,37,32)(35,38,39,40)(9,10)(11,12)(13,16)(14,15)(17,20)(18,19)(21,23)(22,24)(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.