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