There are a number of graphs associated with J. H. Conway.
The first is the unique rank-3 strongly regular graph with parameters
with spectrum
(Brouwer and van Maldeghem 2022, p. 359).
A second is the unique rank-3 strongly regular graph with parameters
and spectrum .
This graph may be constructed in the Leech lattice
(Brouwer and van Maldeghem 2022, pp. 365-366).
Brouwer, A. E. and van Maldeghem, H. "The Conway Graph of 1408 Vertices" and "The Conway Graph on 2300 Vertices." §10.81
and 10.88 in Strongly
Regular Graphs. Cambridge, England: Cambridge University Press, pp. 359
and 365-366, 2022.
with spectrum 
(Brouwer and van Maldeghem 2022, p. 359).
and spectrum 
.
This graph may be constructed in the Leech lattice
(Brouwer and van Maldeghem 2022, pp. 365-366).
