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