Playing closed-voiced triads is relatively easy once you memorize all the intervals between adjacent tones. For example: in ascending order, a major triad, root position has a major third, then a minor third. In first inversion, the same triad has a minor third, then a perfect fourth. In second inversion, there's a perfect fourth, then a major third.
Open voicings are a only bit more challenging but potentially very rewarding. Using the same example as above, an open-voiced major triad in root position has a perfect fifth, then a major sixth. In first inversion, there is a minor sixth, then a perfect fifth. In second inversion, there's a major sixth, then a minor sixth. Because some voices are not on adjacent strings, playing open voiced triads requires selective string muting for chords and string skipping for arpeggios, so it will take a little more effort to learn.
While the above is not terribly specific to guitar, it's not especially difficult to translate general musical information about intervals to fretboard fingerings/shapes. Knowing the intervals in triads, combined with knowledge of the intervals between string pairs, enables the player to learn and execute triads with minimal effort, both as chords and as arpeggios. IMO it's better to learn the shapes/fingerings on your own directly from knowledge of the various intervals than to rely on fretboard diagrams created by someone else.