Actually.. if it's a yound adult dragon... it's an even match... (if one goes by D&D 3.5 rules) As I've made the xenomorph species for it... and the queen compares to a yound adult dragon... (by herself not including horde)
Dragon has flight and breathe weapon.. queen has resistances.. plus she can just go into hiding... who wins? Depends on which one is more cunning in battle tactics.
.... and if the queen can distract the dragon long enough for a facehugger to come romping by... And no sorry.. haven't figured out the rules for adaptation for facehuggers based on other species.. so as yet.. not hybrid xenos in the rules. currently all 'bursted' are of the base xeno race.. which is powerful enough..
And actually.. you want a chestburster on a mindflayer first.. queen from that... then THAT queen having a egg/facehugger on the dragon... get the super intelligence and mental powers.. plus dragon build and powers... equals.... Um... who cares at that point.. we are all slaves.. or food... or... other.. fun stuff.