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