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