If you're not lifting until tomorrow, the soreness may well subside. In the meantime, apply some active recovery techniques. This may include stretching, massage, hot/cold showers, light chest work (a few easy sets of pushups, for example).
I'd still lift if sore, unless you're talking injury-sore. Your ability to set PRs may be affected, but you can still lift. Worse case scenario, assuming you're not injured, you won't hit a PR but there's always next week.
Question -- what did you do to cause pain? Unless you're relatively new to the 5x5 or really pushing hard, I'm a bit surprised if you're that sore and especially if it persists for 2 days. That kind of muscle soreness usually goes away once you adjust to the 5x5 frequency. And even then, if you get sore, it's my experience that it only lasts a day.