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