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