It needn't be that elaborate, unless of course you fancy a challenge
How about this idea then.
Perhaps once the fuel truck has parked up and fuel requested a fuel hose automatically connects from the truck to the underside of the wing. It needn't even be a moving animation, just showing there, in a blink of the eye.
Or
Something like Aerosofts Enhanced Services (see attachment)
Apologies for sending two images the same. The first timed out so I assumed it hadn't gone.