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