I have the same pistol, and the weapon is inherently designed for concealment even deep concealment. I think a open carry for them requires a very obvious holster just to be safe legally. Here are some holsters from NAA's website.
I think this would be ok for OC.
These belt buckle ones are not considered OC from what I understand because they disguise the true nature of the weapon.
I like the idea of the neckchain holsters. Easy to switch from OC to CC, but just becareful of someone trying to rip it off