I found this package:

Fancy Formatting of Partial Derivatives -- from Wolfram Library Archive

Unfortunately, it does not seem to be compatible with new versions of Mathematica. I tried to come up with a quick and dirty fix, which is not particularly elegant but should work fine. Using DFormat[On] should get you what you need. Calling DFormat[Off] switches back to normal.

Code:

denomList[nn_List, vars_List] :=
Block[{i, result = {}},
Do[Which[
TrueQ[nn[[i]] == 0], Null,
TrueQ[nn[[i]] == 1],
result = Join[result, {"\[PartialD]", vars[[i]]}],
True, result = Join[result, {"\[PartialD]", nn[[i]]}] ],
{i, 1, Length[nn]} ];
result]
DFormat[On] :=
(Unprotect[Derivative];
Format[Literal[Derivative[nn__][ff_][vars : (_Symbol ..)]]] :=
If[TrueQ[Plus @@ {nn} == 1],
SequenceForm["\[PartialD]", ff[vars]],
SequenceForm[Superscript["\[PartialD]", Plus @@ {nn}], ff[vars]]]/
SequenceForm @@ denomList[{nn}, {vars}];
Protect[Derivative])
DFormat[Off] :=
(Unprotect[Derivative];
Format[Literal[Derivative[nn__][ff_][vars : (_Symbol ..)]]] =.;
Protect[Derivative])