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