You can't. Site Speed (as the metric is defined in Analytics) is attributed to pages, not users. You can add the typical secondary dimensions when exploring these statistics, but these dimensions don't include users.
You should be able to get a decent idea of page speeds by whatever metrics might be a deciding factor (new vs returning, for example) by ...
[Edited a few times per comments]
Bounce rate and exit rate aren't comparable values. For Page A, the bounce rate is
(sessions where the only hit was a Page A PV) / (sessions that landed on Page A)
whereas exit rate is
(Page A PV that were the last PV of their session) / (all Page A PV)
See Exit Rate vs. Bounce Rate from Analytics Help.
Since your ...