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