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