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