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