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