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