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