Only indirectly are rules provided for creating an item that takes a swift action to activate
The section Creating Magic Items says
Using metamagic feats, a caster can place spells in items at a higher level than normal.
Thus, by incorporating a spell modified by the metamagic feat Quicken Spell into the creation of a custom magic item (therefore substantially increasing one or more prerequisite spells' effective levels therefore the item's market price), the item could possibly be activated as a swift action. Like all custom magic items, however, actually creating such an item hinges upon the GM, but this is, at least, a starting point for negotiations.
Examples of existing items that have as a creation prerequisite the feat Quicken Spell include the spell totem, which is like a minor ring of spell storing except that the wearer can take a swift action to use a stored spell when the wearer assumes animal form, and (with a different kind of activation time yet a similar and interesting effect) the ring of vengeful blood magic, which allows a bloodraging wearer thrice per day to cast as an attack of opportunity a 3rd-level-or-less casting-time-of-1-standard-action-or-less spell.
(Many magic items take a swift action to activate without needing the feat Quicken Spell as a creation prerequisite. However, no guidelines exist for creating these besides, as always, comparing them to existing items.)