One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6,9,11)(7,12,8,10)(14,18)(15,20)(23,27)(26,28)(5,7,9,8)(6,10,11,12)(22,25)(26,28)(13,14,17,18)(15,19,20,16)(21,22)(23,26)(24,25)(27,28)(1,2)(3,4)(5,6)(7,10)(8,12)(9,11)(13,15)(14,19)(16,18)(17,20) involution — undirected(5,8,9,7)(6,10,11,12)(13,16,17,19)(14,15,18,20)(21,23)(22,26)(24,27)(25,28)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.