That is an interesting problem, I am not sure about visualization for differential privacy specifically but it definitely is related to uncertainty visualization. Your sketches remind me of the ggdist R package. There is a publication by the same author titled When(ish) is my bus:
https://www.mjskay.com/papers/chi_2016_uncertain_bus.pdf and this recent paper is on Uncertainty for Set visualization but contains a nice Table 1 that lists papers related to uncertainty visualization in general:
https://drive.google.com/file/d/1xewFIlurPA3_bJoBXxtRenc6MNmIHn3O/view?usp=drivesdk
I am not familiar with all of them but it could be a good starting point.
From Mark Keller at HMS: