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