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