You can achieve your goal with the following:
CSS:
div.paceDiv {
position: absolute;
width: 100%;
height: 100%;
...
display: none;
}
JS:
Pace.on("start", function(){
$("div.paceDiv").show();
});
Pace.on("done", function(){
$("div.paceDiv").hide();
});
Hope it's no too late though!