We consider a puzzle consisting of colored tokens on an $n$-vertex graph, where each token has a distinct starting vertex and a set of allowable target vertices for it to reach,
and the only allowed transformation is to ``sequentially'' move the chosen token along a path of the graph by swapping it with other tokens on the path. This puzzle is a variation of the Fifteen-Puzzle and is solvable in n^3 token-swappings. We thus focus on the problem of minimizing the number of token-swappings to reach the target token-placement. We first give an inapproximability result of this problem, and then show polynomial-time algorithms on trees and complete graphs.