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