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