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