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