Hi,
Since I do not have access to the exact HP printer model, this would be general information.
First of all the interface. An HP Color LaserJet Enterprise CM4540 MFP should be equipped with an internal print server with an Ethernet port.
The easiest way is to connect the printer's Ethernet port to one of the LAN ports of a Wi-Fi router. That would allow computers connected to the same router to print (wirelessly or wired).
If the printer for some reason (location or other) cannot be wired to the Wi-Fi router, you could use an appropriate Wi-Fi range extender with wireless Ethernet bridge capabilities. Edimax EW-7438RPn Mini and TP-Link RE200 are merely two examples. The printer's Ethernet port would be connected to the Wi-Fi extender's corresponding port. The Wi-Fi extender (operating in a client mode) would be wirelessly connected to the Wi-Fi router.
Printing via the above wireless connections would require a computer with working printer drivers for the CM4540.
Now to AirPrint (not to be confused with wireless printing generally). With the driverless AirPrint technology, Mac OS X 10.7 Lion or later Mac computers can print without the need for drivers from the printer manufacturer. AirPrint would also allow iPhones and iPads to print (without special apps). The printer must be a supported AirPrint model. A number of AirPrint models are listed in About AirPrint - Apple Support. Unfortunately, HP's CM4540 does not appear to support AirPrint.
For printers not capable of using AirPrint, there are dedicated AirPrint servers (see the AirPrint print servers list in About AirPrint). However, these may be expensive, and there may be certain limitations.
If you have a spare Mac OS X 10.7 Lion or later Mac, a workaround could possibly be to use a special Mac application like Printopia (https://www.decisivetactics.com/products/printopia/). A demo/trial version is available. The idea is that the old Mac would work as a print server, at least making printing from iPhones/iPads possible (similar to AirPrint).
