In the Perspective view, go to Control Vertex sub-object mode of the newly created EP Curve and adjust the positions of some vertices with Move tool to give a non-straight shape that can be seen in case of such cables in the real-world.

Now create a circle (Create > NURBS Primitives > Circle) for the round shape of the cable. While the circle is still selected, SHIFT+Select the EP Curve. Choose Surfaces menu-set (‘F4’ is the shortcut). Then apply “Extrude” command from Surfaces menu. You should get the following cable shape. If necessary, select the circle and adjust its radius, rotation etc. to get the most appropriate shape for the cable.

We do not need the circle anymore after we get the preferred shape for the cable. So we can delete (by Type) again the History. Now, you can further refine the shape of the cable by adjusting the Control Vertices of the extruded cable shape. You may like to move/scale the vertices more horizontally and less vertically.