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