Short answer - no, I don't know of one. That isn't to say that they don't exist.
There was a very nice parts diagram available, but for the 2003/2004 bikes.
The on-line fiches come with the parts lists and prices, and generally, these are updated as part numbers are modified. The ones I use in the UK also indicates whether the part is in stock, available to order, or whether the part is no longer available. Sometimes, they get this wrong - eg - some sites say that a part is no longer available, but the part was updated and it is the original part that is no longer available. The updated part is still available.
In short - you may find that you need to look at a few sources for reference and for that, the online sources are better.
If you have a '2008' bike, you need to make certain you know which model it is. Many of the parts for the ST1300 have not changed since it was introduced in 2002, and are common across all models. (The rear brake caliper springs to mind). However, the 2008 model introduced a number of very significant changes. You need to know if your bike is actually a 2008 model or a 2006 / 7 model that was sold and registered in 2008. This may be why you can't find your particular model on some fiches. They didn't introduce a new model each year - they continued to build the previous model. I think in the USA, there was no change from 2009 until 2012. In the UK, the 2009 model stayed around until it changed in 2014.
The white label under the seat will give you the model number. The 10th character of the VIN (on the headstock) will give you the model year.
One good company here in the UK is David Silver. I believe he now has a presence in the USA. If you contact them, and give your frame number, they will be able to tell you precisely what model and variation your bike is. Example - I needed a new radiator. Mine is a UK 2009 model that was actually built in late 2013. The 2014 model in the UK has a different radiator, but it turns out that they changed the radiator part way through the production run of the 2009 models. They were able to tell me when the change took place, and from my (VIN) that mine required the later model of radiator.
The only part that attaches to the new radiator that is different from the older models is the radiator cap. So I reckon that the radiator ahs a different fitting for the cap. Which makes the entire radiator £100 cheaper. Yeah. Right !
