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