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