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