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