One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,3,4)(5,6,10,12)(7,8,9,11)(14,18)(15,19)(23,27)(25,28)(5,7,10,9)(6,11,12,8)(13,14,17,18)(15,16,19,20)(21,22,24,26)(23,25,27,28)(6,12)(7,9)(14,18)(16,20)(21,22)(23,25)(24,26)(27,28) involution — undirected(1,2)(3,4)(5,8,10,11)(6,7,12,9)(13,15,17,19)(14,16,18,20)(5,9,10,7)(6,11,12,8)(13,16)(14,19)(15,18)(17,20)(21,23)(22,25)(24,27)(26,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.