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