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