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