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