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)(11,18)(12,20)(13,15)(14,16)(17,21)(19,23)(22,24)(25,26,30,35)(27,32,36,31)(28,33,39,38)(29,34,40,37)(3,7)(5,8)(9,11,15,14)(10,16,13,18)(12,19,21,22)(17,23,20,24)(27,36)(28,39)(31,32)(33,38)(1,2)(3,5)(4,6)(7,8)(25,27)(26,31)(28,37)(29,38)(30,36)(32,35)(33,40)(34,39) involution — undirected(1,3)(2,5)(4,7)(6,8)(9,12)(10,17)(11,19)(13,20)(14,22)(15,21)(16,23)(18,24)(25,27)(26,32)(28,37)(29,33)(30,36)(31,35)(34,39)(38,40) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,13,15,10)(11,16,14,18)(12,20,21,17)(19,23,22,24)(25,28)(26,33)(27,37)(29,32)(30,39)(31,40)(34,36)(35,38)(9,14,15,11)(10,16,13,18)(12,19,21,22)(17,24,20,23)(25,29)(26,34)(27,38)(28,32)(30,40)(31,39)(33,36)(35,37)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.