I would put it as another job title like this: "Founder at XYZ Accelerator"
Below that you should add the following:
List what skills you’ve learned throughout the accelerator. These days accelerators/incubators are more valuable than MBA degrees as you’ve gotten real experience executing rather than learning theory or doing simulated projects in classrooms.
Depending on how selective the accelerator is you can share the acceptance statistics. For example YC has a <1% acceptance rate, that means you’re doing something right if you’re able to get in. Highlighting those numbers will be definitely make you stand out.
Talk about the accomplishments during the accelerator. Where was your startup before the program and where was it after? You should bring that to light.
Mention the network and mentors you’ve gained. Hiring managers will see value in a candidate whose been mentored by entrepreneurs, especially in hopes that you bring that same entrepreneurial spirit to the job.
For any experience you want to highlight, from an acclerator or any other type of organization, I highly recommend using the PAR Statement when you write your résumé. PAR is for Project, Achievement, Results. If you manage to highlight skills that are seeked by employers, then you'll increase your chances of geeting an interview.
I'm sure you have learned a lot from your experience with the accelerator. There's no doubt that you can demonstrate a lot of skills on your résumé.