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