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