How can I load storyboard programmatically from class?

In your storyboard go to the Attributes inspector and set the view controller’s Identifier. You can then present that view controller using the following code.

UIStoryboard *sb = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
UIViewController *vc = [sb instantiateViewControllerWithIdentifier:@"myViewController"];
vc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentViewController:vc animated:YES completion:NULL];