It does not look good, but I wouldn't give up right away. If the plant does recover, it will be really scarred. It will need protection from the sun and/or heat (to the extent you are inland and summer is not a breezy, foggy experience like it mostly is here). Bright light is important but direct sun should be limited to the morning hours, not mid day. Filtered light or brightest shade will work too. Not deep shade.
As a general rule you have do do a gradual stepwise accommodation to the sun when you get a new plant. Assume it was growing in a greenhouse or under shade cloth unless you can confirm with the nursery on the spot that it's been adapted to the sun.
Usually this means a few weeks of moving the plant each week to a slightly more exposed location. Three notes about sunburn: (1) the sun is most intense energetically around the summer solstice (ie. right now); (2) the most intense sun comes at mid day, so overhead protection or shade cloth can be very useful to block or filter those rays; and (3) heat makes plants more vulnerable to sun.
At this point you have to exercise restraint with the water. Always wait for the soil to go dry at depth (not just the surface) before watering. There is no particular advantage to allowing it to sit bone dry for any extended period, but there is an increased risk of rot if it does not dry out enough often enough.
Be aware the soil will go dry slower when a plant is in crisis (not drinking deeply) and when it is receiving shade protection.
