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