In a small bowl, combine salt, thyme, rosemary, marjoram and cayenne pepper. Sprinkle the herb mixture evenly over chicken; rub in with your fingers. For a charcoal grill, grill chicken on the rack of an uncovered grill directly over medium coals for 12 to 15 minutes or till chicken is no longer pink (170 degree F), turning once. (For a gas grill, preheat grill. Reduce heat to medium. Place chicken on grill rack over heat. Cover and grill as above.) Meanwhile, in another small saucepan, heat the Alfredo sauce.