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