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