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