Microchip documentation does not label CAN buss pins on micro controller pinout diagram

The CAN pins do not have fixed pin assignments. Instead you are able to select which of the "Remappable Pins" you wish to use (RP0 through RP15).

If you refer to page 180 of the datasheet, specifically the table titled "REGISTER 11-16" (RPINR26: Peripheral Pin Select Input Register 26), it details the register used to select the CAN RX pin location (C1RXR).

For the CAN TX pin location, this is set by the RPnR register of the pin that you want to use as detailed in section 11.6 (Peripheral Pin Select) starting page 161.

It is considered a 'remappable peripheral'. You will need to map those to pins labelled RPX (where X is some number).

See section 4.8 of your datasheet.