The HP MDS (microwave design system) has an option that will
allow you to read in a spice deck and it will produce a
schematic representation.
Be aware that while the schematic will be correct from a
a connectivity (netlist) standpoint, it will be, shall we say,
aesthetically a mess. The parts are slapped down on the screen
in some arbritrary order and then they are connected with a
ratsnest generated from the netlist info from the spice deck.
In order to make the schematic into something that you can look
at and easily understand you need to spend a bit of time moving
the parts around to a more conventional topology. Fortunately the
wires rubberband so you don't lose the proper connectivity when
you rearrange things.
The MDS package is pretty pricey, especially if you don't have
other uses for it other than doing the spice to schematic generation.
(Fortunately, we do use it for lots of other things).
There may be other software that may accomplish the same thing,
but when I looked around for such a package a few years ago, the only
other thing that I found at the time that was even close in functionality
was somebodies thesis project that really didn't work all that well.
Ray Anderson
Sun Microsystems Inc.