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