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