Some initial thoughts:
(From lowest to highest)
Sorcerers: Seen less as Practitioners of the Art, more as Semi-intelligent magical creatures. Dangerous oddities, who are only "tolerated" within the Order to keep an eye on them. Alternately, they could be seen as the results of "Pure" magical bloodlines (think Harry Potter.) In which case, change their position to the top of the list.
Witch/Hedge Wizard: While still primary casters, their rural connections
make them seem "quaint" or "rustic" to the City-based Ivy League Spellcasters.
Alchemist: The Tradesmen of the order. While not casters per se, they nonetheless enjoy a healthy amount of respect. This is due, in no small part, to the revenue they bring in from the sales of their potions and other Alchemical concoctions. They are the lowest level of the order that receives any sort of respect from the Orders Leaders, as long as they don't try getting above their station!
Magus: The Special Guardsmen of the Order. The smartest candidates are handpicked at an early age from the military academies and taught by both Expert Magi and Battle-Wizards. Their duty is to protect the Order from any threat, foreign or domestic, and as such are given much respect.
Wizards: The leaders of the Order. As the true manipulators of reality, even a low-level Wizard will accord more respect than any except the higher level members of either the Alchemists or Magi. Standards for them will be high, but their power (magical or political) will be worth it.