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