A sullen and nervous Kristen Stewart grabbed the spotlight at the opening of the Toronto film festival late Thursday in the \"Twilight\" star\'s first public appearance since her cheating scandal broke. Stewart, 22, made a public apology in July to her longtime boyfriend and \"Twilight\" co-star Robert Pattinson, 26, for an affair with the director of her last movie \"Snow White and the Huntsman,\" Rupert Sanders. She is in Toronto this week for the North American premiere of Brazilian director Walter Salles\' \"On The Road,\" a film based on Jack Kerouac\'s groundbreaking novel about the freedom of youth. The film also stars Sam Riley, Garrett Hedlund, Viggo Mortensen and Kirsten Dunst. On the red carpet, Stewart showed a \"bit of anxiety, leg trembling,\" reported the daily Globe and Mail. Canadian broadcasters the next morning noted that she always seemed to be looking down during interviews. Stewart had arrived at the Toronto airport Wednesday wearing a T-shirt that \"Twilight\" fans reportedly identified as having once been worn by Pattinson. This was interpreted by fans to mean that their relationship may be on the mend. For \"On The Road,\" Salles teamed up again with Puerto Rican screenwriter Jose Rivera. The duo previously paired up for another unforgettable road movie, \"The Motorcycle Diaries\" (2004).