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